For a long time, drive systems have been fitted into vehicles with slide steering, i.e., in vehicles, such that to drive around a curve the respective driven wheels (or sprocket wheels of a tracked vehicle) on the inside of the curve are slowed relative to the driven wheels on the outside of the curve. In this the continuously variable drive motors allow a largely free choice of the speed ratio between the driven wheel on the inside of the curve and the driven wheel on the outside of the curve. It has been shown, however, that when a transmission arrangement with a fixed transmission ratio is connected downstream from continuously variable drive motors, the latter comes up against their limits so far as final speed and drive torque are concerned. A further disadvantage is considered to be that for reasons of available space, it is often difficult to fit next to one another two drive aggregates arranged out of alignment with one another. Each consists of a drive motor, transmission arrangement and wheel in the direction of the rotation axis of the driven wheel pair and to design a driven axle arrangement for them.
From the unpublished DE 10 2005 010 514A, a drive system for individually driving two driven wheels of a driven wheel pair or the like for a vehicle is known. The drive system comprises two continuously variable drive machines each of which is in drive connection, via a transmission arrangement, with an associated driven wheel or the like. The transmission arrangement comprises two respective transmission units arranged one behind the other. One of the transmission units being designed as a shift transmission and the other transmission unit as a bevel gear transmission with a fixed ratio.
This drive train solves both of the technical problems outlined in that for each driven wheel two transmission units are used. One of the transmission units is designed to enable the transmission ratio to be changed and the other transmission unit to improve the installation circumstances. With the help of a two-stage shift transmission, two-speed or drive torque ranges can be preselected, while the bevel gear transmission makes it possible to arrange the drive machines and, if necessary, one of the two transmission units perpendicular to the rotational axis of the driven wheels.
The respective shift transmission of the transmission units is made as a two-stage planetary gearset in which the sun gear wheel is connected to a drive input shaft and the planetary gear carrier to a drive output shaft. A ring gear wheel of this planetary transmission can optionally be locked in a rotationally fixed manner or coupled to the drive output shaft. In addition, the shift transmission is arranged downstream from the drive machine and the bevel gear transmission downstream from that transmission.
Although this drive system is advantageous, nevertheless, it is desirable to further develop such a drive system in such a manner that it can be used without major structural modifications for different types of vehicles, with structural space situations and distances of the drive aggregates above the road that deviate from one another.
Against this background, the purpose of the invention is to provide a drive system of the type just outlined, which enables the final speed or drive torque to be varied and which is easier to fit into a vehicle. In addition, the drive system should be designed such that it can be used in different vehicle types, fitting space situations and distances of the drive aggregates above the ground, with only slight structural alterations using most of the same drive system components.